167 



Genus STREBLOTRYPA. Ulrich. 



[Ety. : Strebhs, turned about; trypa, opening.] 

 (1890: Geo. Surv. 111., Vol. VIII., p. 403.) 



Bryozoum resembling Rhombopora in structure and form, 

 but having angular pits between the ends of the apertures, 

 and irregular cells, or mesopores, in the inter-apertural 

 spaces. 



Streblotryfa hamiltonense. (Nicholson.) (Fig. 59.) 

 (Pal. N. Y., Vol. VI., p. 191, PI. LV.) 



Distinguishing Characters. — "Cells tubular, arising from a 

 filiform axis at the center of the branch . . . ' [This char- 

 acter would place the species under Acan- 

 thoclema (Hall), under which genus it was 

 described in Vol. VI., Pal. N. Y.] ; oval cell 

 apertures in longitudinal parallel rows, often 

 alternating, separated by prominent longi- 

 tudinal ridges ; ridges usually slightly sinu- 

 ous; two angular pits between apertures. 



Found in the "Hamilton group, West Hamburg, Erie 

 County, N. Y." (Hall.) Found also at Avery's Creek, in the 

 shale below the Trilobite beds (rare). 



Fig. 59. Streblotrypa 

 hamiltonense. Natu- 

 ral size, and fragment 

 enlarged, x 12 (after 

 Hall and Simpson). 



Genus FISTULICELLA. Simpson. 



[Ety.: Fistula, pipe; cella, cell.] 

 (1894: 14th Rep't N. Y. State Geol., p. 606.) 



"The manner of growth and general appearance is the 

 same as that of Lichenalia, but the cells are circular and 

 without pseudosepta or lunaria." (Type 

 F. plana. Hall.) 



Fistulicella plana. Hall. ( Fig. 60. ) 

 (Pal. N. Y., Vol. VI., p. 215, PI. LVI1I.) 



Distinguishing Characters. — Thin, lam- 

 ellate expansions, incrusting or free; cir- 

 cular apertures, regularly or irregularly 

 disposed ; circular or elongate, depressed 

 maculae, without cells; adjacent apertures 

 slightly larger than those on genera 1 surface. 



x/2 



Fig. 60. Fistulicella 

 planet. Enlargement 

 of a portion ol the sur- 

 face, x 12 (after Hall 

 and Simpson). 



